The Magaliesberg are among the oldest mountains in the world, almost 100 times older than Everest. They stretch for 120km from Bronkhorstspruit Dam east of Pretoria to Rustenburg in the west and separate the highveld grasslands to the south from the bushveld savannah in the north.
Hamerkop Kloof, (VCC) one of the many beautiful kloofs to explore in the Magaliesberg.
Mountain climbing enthusiasts have visited the Magaliesberg since the 1920s. It is one of the main sites for the Johannesburg section of the Mountain Club of South Africa, which has always promoted conservation in the area, and has spared it from much abuse. Further information on conservation and climbing in the Magaliesberg can be obtained from their website www.jhb.mcsa.org.za. Today much of the area is a protected natural environment that deserves and requires the co-operation and care of the many thousands of visitors who come to the mountains to seek sanctuary from the stress of city life.
Click here to find out more about the geology and formation of the mountains…Geology
The ancient geological structure of the Magaliesberg is evident for almost its entire length. Creation of these mountains began almost 2,300 million years ago when Africa was part of what was then a large landmass called Gondawanaland and most of what is now known as the Transvaal was submerged under shallow water. This “sea” of salty water was surrounded by 3000 million year old granite called the Auchaean Basement Complex from which fragments of white quartzite, pebbles, sand and silt were eroded and eventually created a layer of sedimentary rock on the bed of the sea, known today as the “Black Reef”..Dolomite and Chert
Another layer known as the Malmani Subgroup, was added to this sea bed when algae developed in the saline water and combined with silica that leached from the Basement Complex to produce a carbonate deposit which eventually compressed into layers of rock many kilometers thick. In some places it formed dolomite, a semi-soluble limestone, and in other places it formed chert, which is less soluble than limestone.Underground water sources.
Over millions of years once the rock had solidified, water seeped in and dissolved parts of the dolomite leaving huge caves, some of which became underground reservoirs, and these are the source of many of the streams that flow through the region. Other caves like Sterkfontein cave, were formed when the dolomite tilted above the level of the water table.
The Skurweberg and Krokodilberg range of hills south of the Magaliesberg were formed where there was more chert than dolomite. The dolomite was deposited into the valleys and the chert remained to form the ridges of hills.Quartzite and Shale
Eventually the water dried up and other deposits known as the Pretoria Group were made on the bed. These were quartzite, made from beach sand washed down from the shores onto the seabed and eventually crystallized into extremely hard, weatherproof rock. Today quartzite can still be seen that bears the ripple marks of the original ancient sandy sea bed. Shale came from muddy silt that formed when there was more moisture and created layers between the quartzite. This process went on over 300 million years in four different stages and resulted in what is known as the Timeball Hill Formation.
The mountains and hills that are evident from this quartzite and shale strata are Salvokop behind the Pretoria railway station, and Daspoort, Magaliesberg and Smelterskop formations. Magaliesberg was the deepest deposit and the resistant quartzite formed the precipitous cliffs that can be seen on these and other mountain ridges.The Bushveld Complex
About 2000 million years ago a massive geological phenomenon occurred during what is known as the Bushveld Complex. Deep beneath the surface of the earth molten magma began to build up pressure. It formed a 65000 sq km reservoir of liquid rock and intruded between all the sedimentary layers of the Transvaal Sequence. As the magma seeped in, the weaker, older structure of the Transvaal Sequence subsided and and slabs of rocks thousands of meters thick tilted into the molten magma, forming jagged ranges of mountains around the basin.. . This magma intrusion resulted in a wide variety of igneous rocks that contain considerable mineral wealth. North of the mountains many ores are found – manganese, vanadium, nickel, tin, chrome, vast quantities of iron ore and the richest platinum deposits in the world.
Over the millennia the exposed edges of the tilted rocks were weathered by ice and the elements to form the mountains we see today In the south it broke out into parallel ridges, the highest of which is the Magaliesberg.
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